Chronic effect of smoking upn pulmonary distribution of ventilation in healthy males.
D000328:Adult; D000367:Age Factors; D006801:Humans; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000032:analysis; D012119:Respiration; D012907:Smoking; D013147:Spirometry; D013997:Time Factors
D009584:Nitrogen